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Nuclear relaxation of the water protons included in (SN)x crystals
iv
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN THE J. PHYS. CHEM. SOLIDS
These results are then used to discuss experimental data for NaCl and KC1 containing divalent cations and for alkaline earth fluorides containing trivalent rare earth ions. Received 10 March 198 1 Revised 14July 1981 13.
NUCLEAR RELAXATION OF THE WATER PROTONS INCLUDED IN (SN), CRYSTALS H. Nishihara, I. Nakada and K. Satoh, Institute for Solid State Physics, University of Tokyo, Roppongi, Tokyo 106, Japan.
The temperature and frequency dependences of the proton spin-lattice relaxation time in Hz0 included in (SN), crystals have been measured and discussed. It is suggested that a significant amount of water is adsorbed on the surface of the (SN), fibers. Received 3 December 1980 Revised 6 August 198 1 14.
EFFECT OF TEMPERATURE AND PRESSURE ON THE RAMAN SPECTRUM OF As4S3
T. Chattopadhyay, C. Carlone, A. Jayaraman and H.G. v. Schnering, Max-Planck-Institut fur Festkorperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany. The Raman spectrum of crystalline As4S3 has been investigated as a function of temperature from 4 to 430 K at ambient pressure, and as a function of pressure to 70kbar at ambient temperature. The external mode frequencies which appear clearly separated from the internal modes exhibit stronger pressure and temperature sensitivity compared to the latter modes. At the p-As4S3 to o-As& phase transition near 410 K, the external modes change discontinuously indicating a firstorder phase transition. The internal mode frequencies remain practically unaffected. There is no crystalline to plastic transition in As4S3, as in the case of P4S3. The dv/dP and dv/dT data are analyzed using well established approaches. Application of non-hydrostatic pressure (> 60 kbar) appears to destroy the crystallinity of As4S3. Received 1 Jr@ 198 1 15.
ELECTRIC FIELD GRADIENT, ANISOTROPIC SHIFT, TETRAHEDRAL SITE OCCUPATION, AND ATOMIC MOTION IN Li,Ti& R.L. Kleinberg, Schlumberger-Doll Research, P.O. Box 307, Ridgefield, CN 06877, U.S.A.
Vol. 41, No. 9
New measurements of NMR lineshape parameters and relaxation rates have been made to characterize a carefully prepared set of samples of Ii,TiSs , with x spanning the composition range from one-tenth to one. Electric quadrupole coupling constants are in general agreement with previous measurements, but display differences at the high end of the composition range and an unpredicted upturn as x tends toward zero. An anisotropic shift of the line has been discovered and its possible origins are discussed. An unexpected discontinuity in the linewidthcomposition relation may be due to lithium occupation of tetrahedral sites at the level of a few percent. Lithium hopping rates derived from continuous wave NMR and pulsed NMR measurements are found to agree quite well with one another. Received 13 April 1981 Revised 3 August 198 1
16.
STRUCTURE, ELECTRICAL, TRANSPORT AND OPTICAL PROPERTIES OF A NEW ORDERED IRON INTERCALATED DICHALCOGENIDE, Fec,,TiSez J.W. Lyding, M.T. Ratajack and C.R. Kannewurf, Department of Electrical Engineering and Computer Science and the Materials Research Center, Northwestern University, Evanston, IL 60201, U.S.A.; W.H. Goodman and James A. Ibers, Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, IL 60201, U.S.A.; and Richard E. Marsh, Department of Chemistry, California Institute of Technology, Pasadena, CA 9 1125, U.S.A.
The compound Fee_,TiSe, crystallizes in space groups D&P3m 1 of the trigonal system with 8 formula units in a cell of dimensions a = 7.148 (4) c = 11.880(7)a at 117 K. The structure of Fe,.%TiSes can be derived from that of TiSes by insertion of Fe atoms into some of the octahedral holes between the layers. No two adjacent octahedral holes along c contain Fe atoms, that is no two Fe atoms are related by a translation of c/2. The compound Fe,TiSe, ,x = 0.34, exhibits physical properties remarkably different from those found in either the host material, TiSe,, or in low iron concentration (x < 0.2) intercalated materials. The electrical resistivity of this compound exhibits a sharp decrease below 120 K which is coincident with a well defined peak in the Hall coefficient. These data have been interpreted as the onset of antiferromagnetic ordering as suggested by results of magnetic susceptibility measurements. Optical reflectance measurements indicate a simple Drude-like free carrier behavior and are
ABSTRACTS OF ARTICLES TO BE PUBLISHED IN THE J. PHYS. CHEM. SOLIDS
These results are then used to discuss experimental data for NaCl and KC1 containing divalent cations and for alkaline earth fluorides containing trivalent rare earth ions. Received 10 March 198 1 Revised 14July 1981 13.
NUCLEAR RELAXATION OF THE WATER PROTONS INCLUDED IN (SN), CRYSTALS H. Nishihara, I. Nakada and K. Satoh, Institute for Solid State Physics, University of Tokyo, Roppongi, Tokyo 106, Japan.
The temperature and frequency dependences of the proton spin-lattice relaxation time in Hz0 included in (SN), crystals have been measured and discussed. It is suggested that a significant amount of water is adsorbed on the surface of the (SN), fibers. Received 3 December 1980 Revised 6 August 198 1 14.
EFFECT OF TEMPERATURE AND PRESSURE ON THE RAMAN SPECTRUM OF As4S3
T. Chattopadhyay, C. Carlone, A. Jayaraman and H.G. v. Schnering, Max-Planck-Institut fur Festkorperforschung, Heisenbergstrasse 1, D-7000 Stuttgart 80, Federal Republic of Germany. The Raman spectrum of crystalline As4S3 has been investigated as a function of temperature from 4 to 430 K at ambient pressure, and as a function of pressure to 70kbar at ambient temperature. The external mode frequencies which appear clearly separated from the internal modes exhibit stronger pressure and temperature sensitivity compared to the latter modes. At the p-As4S3 to o-As& phase transition near 410 K, the external modes change discontinuously indicating a firstorder phase transition. The internal mode frequencies remain practically unaffected. There is no crystalline to plastic transition in As4S3, as in the case of P4S3. The dv/dP and dv/dT data are analyzed using well established approaches. Application of non-hydrostatic pressure (> 60 kbar) appears to destroy the crystallinity of As4S3. Received 1 Jr@ 198 1 15.
ELECTRIC FIELD GRADIENT, ANISOTROPIC SHIFT, TETRAHEDRAL SITE OCCUPATION, AND ATOMIC MOTION IN Li,Ti& R.L. Kleinberg, Schlumberger-Doll Research, P.O. Box 307, Ridgefield, CN 06877, U.S.A.
Vol. 41, No. 9
New measurements of NMR lineshape parameters and relaxation rates have been made to characterize a carefully prepared set of samples of Ii,TiSs , with x spanning the composition range from one-tenth to one. Electric quadrupole coupling constants are in general agreement with previous measurements, but display differences at the high end of the composition range and an unpredicted upturn as x tends toward zero. An anisotropic shift of the line has been discovered and its possible origins are discussed. An unexpected discontinuity in the linewidthcomposition relation may be due to lithium occupation of tetrahedral sites at the level of a few percent. Lithium hopping rates derived from continuous wave NMR and pulsed NMR measurements are found to agree quite well with one another. Received 13 April 1981 Revised 3 August 198 1
16.
STRUCTURE, ELECTRICAL, TRANSPORT AND OPTICAL PROPERTIES OF A NEW ORDERED IRON INTERCALATED DICHALCOGENIDE, Fec,,TiSez J.W. Lyding, M.T. Ratajack and C.R. Kannewurf, Department of Electrical Engineering and Computer Science and the Materials Research Center, Northwestern University, Evanston, IL 60201, U.S.A.; W.H. Goodman and James A. Ibers, Department of Chemistry and the Materials Research Center, Northwestern University, Evanston, IL 60201, U.S.A.; and Richard E. Marsh, Department of Chemistry, California Institute of Technology, Pasadena, CA 9 1125, U.S.A.
The compound Fee_,TiSe, crystallizes in space groups D&P3m 1 of the trigonal system with 8 formula units in a cell of dimensions a = 7.148 (4) c = 11.880(7)a at 117 K. The structure of Fe,.%TiSes can be derived from that of TiSes by insertion of Fe atoms into some of the octahedral holes between the layers. No two adjacent octahedral holes along c contain Fe atoms, that is no two Fe atoms are related by a translation of c/2. The compound Fe,TiSe, ,x = 0.34, exhibits physical properties remarkably different from those found in either the host material, TiSe,, or in low iron concentration (x < 0.2) intercalated materials. The electrical resistivity of this compound exhibits a sharp decrease below 120 K which is coincident with a well defined peak in the Hall coefficient. These data have been interpreted as the onset of antiferromagnetic ordering as suggested by results of magnetic susceptibility measurements. Optical reflectance measurements indicate a simple Drude-like free carrier behavior and are